Sen. Elizabeth Warren, D-Mass., who is gearing up for a potential 2020 presidential bid, has released a DNA test that suggests she has a distant Native American ancestor, part of an extraordinary effort to discredit President Donald Trump and others who have questioned her claims about her heritage.

A report distributed by Warren concludes that there is "strong evidence" that the senator had a Native American in her family tree dating back six to 10 generations. The test results, after first being reported by the Boston Globe, were widely distributed to reporters Monday morning (Oct. 15) by Warren's Senate campaign committee, along with a video on her upbringing and a link to a new "fact squad" website that seeks to debunk critics of her heritage.

The DNA analysis, by Carlos D. Bustamante, a Stanford University professor, concludes that "the vast majority" of Warren's ancestry is European but that "the results strongly support the existence of an unadmixed Native American ancestor in the individual's pedigree, likely in the range of 6-10 generations ago."

That timing fits Warren's family lore, passed down during her Oklahoma upbringing, that her great-great-great-grandmother, O.C. Sarah Smith, was at least partially Native American, the Globe reported.

If Warren's great-great-great-grandmother was Native American, that puts her at 1/32nd American Indian. If the ancestor was 10 generations back, she would be 1/512th Native American.

Trump has frequently mocked Warren's claims about her heritage, calling her "Pocahontas." During a freewheeling phone interview with Fox News last week, he asserted that the senator "faked her heritage," adding: "I have more Indian blood in me than her, and I have none."

The video distributed by Warren's campaign begins with Trump's comments and features several people in Oklahoma, including some Republicans, saying they find them offensive.

Warren then narratives her family history.

"My mother was born in eastern Oklahoma," she says. "It had been Indian territory until just a few years earlier, when it had become a state. My daddy always said he fell head over heels in love with my mother the first time he saw her."

But she recounts that her father's parents were "bitterly opposed" to a marriage because her mother's family was partly Native American. So the couple eloped, she says.